feat(sense): T-X5 云端评判晋升表×conformal 双闸门——本地档自动接管（采纳 cortiq promotion）

- gateway/sense/promotion.py：PromotionTable 状态机（candidate/promoted/demoted）
  * 晋升门：n_total>=n_min 且 通过率>=promote_lb 且 soak 浸泡期满足
  * 退化：promoted 期间通过率<demote_lb 自动降级；降级后可凭数据恢复
  * 一票否决：tier=T3 观察不进通过率统计，已晋升者立即降级
  * 持久化 sense_promotion 表（CREATE IF NOT EXISTS 幂等）
- grader：live 模式对已晋升标签的 T2 决策（无 T3 信号/非 fallback）升级 T1，
  hard_gates.promotion_applied 如实标注；T1/T3/fallback 路径不受影响
- 回填链路：T1 审计抽样带 promo:<label> 标签 -> 人工 verdict approve=ok
  经 /review/{id} 提交时回填晋升表（失败不影响审核主流程）
- 双闸门语义：conformal 阈值保证单条决策风险率，晋升表保证标签级接管节奏；
  collect 数据不足（n_min 未满）不晋升，全部迁移可经 T-X4 留痕审计

pytest 474 passed（T-X4 后 466 + 8）

gateway/sense/grader.py

@@ -21,6 +21,7 @@ from gateway.sense.decision_cache import DecisionCache
 from gateway.sense.embedder import embed
 from gateway.sense.errors import EmbedderDown
 from gateway.sense.features import gate
+from gateway.sense.promotion import promotion_label
 from gateway.sense.store import json_dumps
 
 
@@ -99,10 +100,11 @@ def _rejected_tiers(fallback: bool, probs: Dict[str, float],
 class Grader:
     """决策器（持有 active 工件缓存；工件/阈值切换后调 invalidate）。"""
 
-    def __init__(self, cfg: SenseConfig, store, observer=None):
+    def __init__(self, cfg: SenseConfig, store, observer=None, promotion=None):
         self.cfg = cfg
         self.store = store
         self.observer = observer
+        self._promotion = promotion         # T-X5：晋升表（可 None）
         self._head: Optional[LinearHead] = None
         self._head_loaded = False
         self._thresholds: Optional[Dict[str, Any]] = None
@@ -194,6 +196,18 @@ class Grader:
             else:
                 tier = "T2"
 
+        # ---- 晋升表应用（T-X5：conformal 之外的统计闸门；仅 live）----
+        # 仅对 T2 决策且无任何 T3 信号时，允许已晋升标签升级 T1；
+        # T1/T3 决策与 fallback 路径不受晋升表影响。
+        promotion_applied = False
+        if (self._promotion is not None and self.cfg.mode == "live"
+                and not fallback and tier == "T2"
+                and not feats.repo_signals
+                and probs.get("t3", 0.0) < float(th.get("t3", 0.9))):
+            if self._promotion.is_promoted(promotion_label(consumer, domain)):
+                tier = "T1"
+                promotion_applied = True
+
         # ---- mode 裁剪（D-G7）----
         if self.cfg.mode == "live":
             executed = tier                                # live：决策即执行
@@ -208,7 +222,8 @@ class Grader:
                         "intent_blocked": feats.intent_blocked,
                         "repo_signals": feats.repo_signals,
                         "over_length": feats.over_length,
-                        "t1_hard_ok": feats.t1_hard_ok},
+                        "t1_hard_ok": feats.t1_hard_ok,
+                        "promotion_applied": promotion_applied},
             thresholds_version=th_version, head_version=head_version,
             mode=self.cfg.mode, fallback=fallback,
             executed_tier=executed)